Hola Eli :-)
en general, son lo mismo... = "tambien".
Por ejemplo "Marcos y yo fuimos al parque. Su amiga, Maria, tambien vino."
Mark and I went to the park, his friend, Mary, came too.
Mark and I went to the park, his friend, Mary, also came.
Mark and I went to the park, his friend, Mary, came as well.
They all indicate the same. Here in the USA, I think that we use "also" and "too" most commonly.